The Starfall ABCs application has 4.5 out of five stars from user reviews on Amazon.com, as of 2015. The majority of the reviews state that the application is effective for teaching children letters and the sounds of those letters.
A review on About.com gives the Starfall website four out of five stars. The review notes the easy-to-navigate website and high-quality content that caters to the needs of young children. It also mentions that the difficulty stays the same for each lesson.
On Amazon.com, many of the negative reviews cite issues with the application not working. The application receives primarily four or five star reviews.